What is the recommended evaluation and management of thyroid eye disease in a patient with Graves disease or autoimmune thyroiditis who presents with new ocular symptoms such as eyelid retraction, proptosis, diplopia, eye pain, or visual changes?

Thyroid Eye Disease: Evaluation and Management

Initial Assessment

All patients presenting with new ocular symptoms in the setting of Graves disease or autoimmune thyroiditis require immediate measurement of proptosis by exophthalmometry, comprehensive screening for compressive optic neuropathy (visual acuity, color vision, visual fields, pupillary response, fundus examination), and documentation of diplopia in primary and reading positions. 1

Essential Diagnostic Workup

• Obtain orbital CT or MRI to confirm tendon-sparing enlargement of extraocular muscles—most commonly the inferior rectus followed by medial rectus—and quantify proptosis. 2, 1
• Measure binocular visual fields to map the region of single binocular vision and assess duction deficits. 2
• Perform optical coherence tomography and Humphrey visual fields to screen for or monitor compressive optic neuropathy. 2
• Coordinate thyroid function testing and thyroid-stimulating hormone receptor antibody levels with endocrinology, as these antibodies are detectable in >95% of patients and correlate with disease activity and severity. 3

Critical caveat: Patients may present as hyperthyroid, hypothyroid, or euthyroid; up to 5% have no thyroid dysfunction at presentation. 2, 3

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Risk Stratification and Disease Severity

Mild Disease (77% of cases)

• Minimal soft tissue congestion, mild lid retraction, no diplopia in primary or reading gaze, no optic nerve involvement. 3

Moderate-to-Severe Disease (22% of cases)

• Significant proptosis, restrictive myopathy causing diplopia, marked soft tissue inflammation, Clinical Activity Score (CAS) ≥3. 1, 3

Sight-Threatening Disease (1% of cases)

• Compressive optic neuropathy (decreased acuity, color vision loss, afferent pupillary defect, visual field defects) or severe exposure keratopathy with corneal ulceration. 1, 3

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Management Algorithm by Disease Severity

For Mild Disease Without Diplopia or Optic Nerve Involvement

Conservative management with ocular surface protection and risk factor modification is the appropriate initial approach. 1

• Prescribe artificial tears and lubricating ointments regularly to prevent exposure keratopathy from lid retraction and mild proptosis. 2, 1
• Add punctal plugs when lubrication alone is insufficient to improve tear retention. 2, 1
• Mandate immediate smoking cessation—smoking is the strongest modifiable risk factor and dramatically worsens disease severity and treatment response. 2, 1, 4
• Supplement selenium (in patients with documented selenium deficiency) to reduce inflammatory symptoms through antioxidant effects. 2, 1
• Observe closely as long as no diplopia develops in primary or reading gaze and no signs of optic neuropathy emerge. 2, 1

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For Moderate-to-Severe Active Disease (CAS ≥3)

Teprotumumab is the first-line treatment for active moderate-to-severe thyroid eye disease, demonstrating superior proptosis reduction compared to intravenous methylprednisolone. 1, 3

• Teprotumumab (a human monoclonal antibody IGF-1R inhibitor) reduces proptosis and Clinical Activity Score in patients with active disease. 2, 1
• Before initiating teprotumumab, establish baseline audiometry and counsel patients about hearing risk—hearing impairment occurs in approximately 30% of patients and may be permanent. 1, 3
• Additional side effects include hyperglycemia; teprotumumab is contraindicated in pregnancy. 1
• Alternative: Intravenous methylprednisolone remains the treatment of choice in many parts of the world due to teprotumumab's high cost, side-effect profile, and high relapse rate. 3
• For steroid-resistant cases, tocilizumab (interleukin-6 receptor blocker) is an effective alternative. 3
• Orbital radiotherapy may be used as a steroid-sparing adjunct in moderate disease. 4, 5, 6

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For Sight-Threatening Disease (Compressive Optic Neuropathy or Severe Exposure Keratopathy)

Urgent orbital decompression, high-dose intravenous corticosteroids, or orbital radiation must be initiated immediately without delay when compressive optic neuropathy or corneal ulceration threatens vision. 2, 1

• Do not postpone decompression surgery while attempting medical therapy when vision loss, afferent pupillary defect, or abnormal color vision is present. 1
• Deep medial orbital wall and floor decompression rapidly relieves compressive optic neuropathy and alleviates inflammatory features of raised orbital pressure. 5
• For severe exposure keratopathy, retractor recession with or without suture tarsorrhaphy protects the ocular surface. 5

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Surgical Rehabilitation Sequence (After Disease Stabilization)

Surgery must be delayed until the inflammatory phase has subsided and the angle of deviation has been stable for at least 6 months. 2, 1

Mandatory Surgical Order

1. Orbital decompression first (if needed for proptosis or prior optic neuropathy). 2, 1
2. Strabismus surgery second to address diplopia—decompression commonly worsens or creates new strabismus. 2, 1
3. Eyelid surgery last to correct retraction—earlier surgeries affect lid position. 1

Strabismus Surgery Technical Considerations

• Recession of restricted muscles (especially inferior rectus) is the mainstay; resection is generally avoided in restrictive disease. 1
• Vertical deviations are more challenging than horizontal (66% vs 84% success after primary surgery) because the inferior rectus is most commonly affected. 1
• Counsel patients preoperatively that recession of restricted muscles will typically increase proptosis; concurrent evaluation for decompression is required when significant proptosis coexists. 2, 1
• Inferior rectus recession carries specific risks: lower lid retraction, consecutive hypertropia, and A-pattern exotropia in downgaze. 1
• Absorbable sutures (6-0 polyglactin) are generally preferred; non-absorbable sutures may reduce postoperative drift in large inferior rectus recessions. 1

Nonsurgical Diplopia Management During Active Phase

• Fresnel or ground-in prisms provide temporary relief while awaiting definitive treatment or for small residual deviations. 2, 1
• Chemodenervation during active phase may provide temporary diplopia relief and possibly reduce final misalignment. 2, 1

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Critical Pitfalls to Avoid

• Do not perform strabismus surgery during active inflammation—the deviation will continue to change. 1
• Do not perform eyelid surgery before strabismus repair—muscle surgery affects lid position. 1
• Do not underestimate the complexity of vertical deviations, particularly inferior rectus involvement. 1
• Do not assume ocular myositis without first evaluating thyroid function—thyroid eye disease is far more common and presents with identical periorbital edema, restricted extraocular movement, and soft tissue congestion. 1
• Do not forget that bilateral (often asymmetric) presentation in a middle-aged adult strongly favors thyroid eye disease over other orbital inflammatory conditions. 1, 7

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Multidisciplinary Coordination

Management requires coordination between endocrinology (to achieve and maintain euthyroid status), ophthalmology (oculoplastics for decompression and lid surgery), and neuro-ophthalmology (for optic neuropathy surveillance). 1 Orthoptists provide valuable assistance under ophthalmologist supervision for complex strabismus assessment. 1